Graphene has emerged as an exciting atomically thin material for fundamental studies and applications in electronics and other applications. Pristine graphene can be obtained through a mechanical exfoliation approach to break the weak van der Waals forces between adjacent layers of graphite. This exfoliation approach can produce high quality graphene, but often with sizes restricted to a few or a few tens of micrometers. On the other hand, a CVD approach can be used to produce graphene with larger sizes, but typically with a polycrystalline structure and a high density of domain or grain boundaries, leading to highly variable electronic properties. Even though a mobility of CVD graphene within a single domain can be comparable to that of exfoliated graphene, the overall transport characteristics of wafer-scale CVD graphene is still largely restricted by crystal defects at domain boundaries. Therefore, achieving large domain, single crystalline graphene represents a challenge for the large-scale fabrication of functional electronic and optoelectronic devices from graphene.
It is against this background that a need arose to develop the CVD process for the growth of graphene described herein.